Since there's been no objection in three days to my query here, I'm undertaking a bit of a project. The current Orange Line route diagram template is somewhat confusing - it has the old Charlestown Elevated and Washington Street Elevated as show/hide options, which makes them look like branches rather than mainline routes, and it doesn't show the Atlantic Avenue Elevated at all.
What I'll be doing here is making a series of roughly five route diagram templates, with shared common sections:
1901-1908: Charlestown Elevated, Atlantic Ave. Elevated, Tremont Street Subway, Washington Elevated to Dudley
1908-1938: Charlestown, Washington Street (to Forest Hills), and Atlantic Ave elevateds; Washington Street Subway
1938-1975: Charlestown and Washington Street elevateds; Washington Street Subway
1975-1987: Washington Street Elevated; Haymarket North extension; Washington Street Subway
1987-present: Southwest Corridor; Haymarket North extension; Washington Street Subway (use current rdt with modifications)
The templates will be on their individual pages, but I'll post them here. Once they're complete, I'll ask around for the okay to move them to a section, either on the main Orange Line page or its own page.